Influence of vertical location and spacing of perforators on perfusion in deep inferior epigastric artery perforator flap breast reconstruction: quantitative analysis using indocyanine green angiography.

[BACKGROUND] This study quantitatively assessed perfusion of the deep inferior epigastric artery perforator (DIEP) flap according to vertical location and vertical spacing of perforators during DIEP flap breast reconstruction.

[METHODS] In 67 patients who underwent unilateral DIEP flap breast reconstruction between November 2018 and August 2021, flap perfusion was intraoperatively assessed using indocyanine green angiography. Perforators located at or above the umbilicus were defined as vertical zone 1 perforators and those below the umbilicus as vertical zone 2 perforators. Perfusion assessment was conducted in two stages: at stage 1, perfusion solely by single dominant perforators was assessed. At stage 2, the perfusion increment effected by adding a single additional perforator was assessed. Perfused area proportions were compared between patients with dominant perforators in zone 1 versus zone 2. The effect of adding an additional perforator to another vertical zone ("vertical spacing") was also assessed.

[RESULTS] The perfused proportion was significantly higher among vertical zone 2 perforators compared with zone 1 perforators in the evaluation of single dominant perforators (70% 56%; P<0.001). In the evaluation of incremented perfusion by single additional perforators, the perfused proportion was significantly higher in the vertical-spacing group compared to the no-vertical-spacing group (17% 12%; P=0.004). Fat necrosis developed in 4.5 percent of the patients over at least 6 months of follow-up.

[CONCLUSIONS] DIEP flap perfusion can be affected by the vertical location of perforators, and flap perfusion can be augmented effectively by vertical spacing of perforators.